/* FileSaver.js
 * A saveAs() FileSaver implementation.
 * 2013-12-27
 *
 * By Eli Grey, http://eligrey.com
 * License: X11/MIT
 *   See LICENSE.md
 */

/*global self */
/*jslint bitwise: true, regexp: true, confusion: true, es5: true, vars: true, white: true,
  plusplus: true */

/*! @source http://purl.eligrey.com/github/FileSaver.js/blob/master/FileSaver.js */

var saveAs = saveAs
  || (typeof navigator !== "undefined" && navigator.msSaveOrOpenBlob && navigator.msSaveOrOpenBlob.bind(navigator))
  || (function(view) {
        "use strict";
        var
                  doc = view.document
                  // only get URL when necessary in case BlobBuilder.js hasn't overridden it yet
                , get_URL = function() {
                        return view.URL || view.webkitURL || view;
                }
                , URL = view.URL || view.webkitURL || view
                , save_link = doc.createElementNS("http://www.w3.org/1999/xhtml", "a")
                , can_use_save_link =  !view.externalHost && "download" in save_link
                , click = function(node) {
                        var event = doc.createEvent("MouseEvents");
                        event.initMouseEvent(
                                "click", true, false, view, 0, 0, 0, 0, 0
                                , false, false, false, false, 0, null
                        );
                        node.dispatchEvent(event);
                }
                , webkit_req_fs = view.webkitRequestFileSystem
                , req_fs = view.requestFileSystem || webkit_req_fs || view.mozRequestFileSystem
                , throw_outside = function (ex) {
                        (view.setImmediate || view.setTimeout)(function() {
                                throw ex;
                        }, 0);
                }
                , force_saveable_type = "application/octet-stream"
                , fs_min_size = 0
                , deletion_queue = []
                , process_deletion_queue = function() {
                        var i = deletion_queue.length;
                        while (i--) {
                                var file = deletion_queue[i];
                                if (typeof file === "string") { // file is an object URL
                                        URL.revokeObjectURL(file);
                                } else { // file is a File
                                        file.remove();
                                }
                        }
                        deletion_queue.length = 0; // clear queue
                }
                , dispatch = function(filesaver, event_types, event) {
                        event_types = [].concat(event_types);
                        var i = event_types.length;
                        while (i--) {
                                var listener = filesaver["on" + event_types[i]];
                                if (typeof listener === "function") {
                                        try {
                                                listener.call(filesaver, event || filesaver);
                                        } catch (ex) {
                                                throw_outside(ex);
                                        }
                                }
                        }
                }
                , FileSaver = function(blob, name) {
                        // First try a.download, then web filesystem, then object URLs
                        var
                                  filesaver = this
                                , type = blob.type
                                , blob_changed = false
                                , object_url
                                , target_view
                                , get_object_url = function() {
                                        var object_url = get_URL().createObjectURL(blob);
                                        deletion_queue.push(object_url);
                                        return object_url;
                                }
                                , dispatch_all = function() {
                                        dispatch(filesaver, "writestart progress write writeend".split(" "));
                                }
                                // on any filesys errors revert to saving with object URLs
                                , fs_error = function() {
                                        // don't create more object URLs than needed
                                        if (blob_changed || !object_url) {
                                                object_url = get_object_url(blob);
                                        }
                                        if (target_view) {
                                                target_view.location.href = object_url;
                                        } else {
                        window.open(object_url, "_blank");
                    }
                                        filesaver.readyState = filesaver.DONE;
                                        dispatch_all();
                                }
                                , abortable = function(func) {
                                        return function() {
                                                if (filesaver.readyState !== filesaver.DONE) {
                                                        return func.apply(this, arguments);
                                                }
                                        };
                                }
                                , create_if_not_found = {create: true, exclusive: false}
                                , slice
                        ;
                        filesaver.readyState = filesaver.INIT;
                        if (!name) {
                                name = "download";
                        }
                        if (can_use_save_link) {
                                object_url = get_object_url(blob);
                                // FF for Android has a nasty garbage collection mechanism
                                // that turns all objects that are not pure javascript into 'deadObject'
                                // this means `doc` and `save_link` are unusable and need to be recreated
                                // `view` is usable though:
                                doc = view.document;
                                save_link = doc.createElementNS("http://www.w3.org/1999/xhtml", "a");
                                save_link.href = object_url;
                                save_link.download = name;
                                var event = doc.createEvent("MouseEvents");
                                event.initMouseEvent(
                                        "click", true, false, view, 0, 0, 0, 0, 0
                                        , false, false, false, false, 0, null
                                );
                                save_link.dispatchEvent(event);
                                filesaver.readyState = filesaver.DONE;
                                dispatch_all();
                                return;
                        }
                        // Object and web filesystem URLs have a problem saving in Google Chrome when
                        // viewed in a tab, so I force save with application/octet-stream
                        // http://code.google.com/p/chromium/issues/detail?id=91158
                        if (view.chrome && type && type !== force_saveable_type) {
                                slice = blob.slice || blob.webkitSlice;
                                blob = slice.call(blob, 0, blob.size, force_saveable_type);
                                blob_changed = true;
                        }
                        // Since I can't be sure that the guessed media type will trigger a download
                        // in WebKit, I append .download to the filename.
                        // https://bugs.webkit.org/show_bug.cgi?id=65440
                        if (webkit_req_fs && name !== "download") {
                                name += ".download";
                        }
                        if (type === force_saveable_type || webkit_req_fs) {
                                target_view = view;
                        }
                        if (!req_fs) {
                                fs_error();
                                return;
                        }
                        fs_min_size += blob.size;
                        req_fs(view.TEMPORARY, fs_min_size, abortable(function(fs) {
                                fs.root.getDirectory("saved", create_if_not_found, abortable(function(dir) {
                                        var save = function() {
                                                dir.getFile(name, create_if_not_found, abortable(function(file) {
                                                        file.createWriter(abortable(function(writer) {
                                                                writer.onwriteend = function(event) {
                                                                        target_view.location.href = file.toURL();
                                                                        deletion_queue.push(file);
                                                                        filesaver.readyState = filesaver.DONE;
                                                                        dispatch(filesaver, "writeend", event);
                                                                };
                                                                writer.onerror = function() {
                                                                        var error = writer.error;
                                                                        if (error.code !== error.ABORT_ERR) {
                                                                                fs_error();
                                                                        }
                                                                };
                                                                "writestart progress write abort".split(" ").forEach(function(event) {
                                                                        writer["on" + event] = filesaver["on" + event];
                                                                });
                                                                writer.write(blob);
                                                                filesaver.abort = function() {
                                                                        writer.abort();
                                                                        filesaver.readyState = filesaver.DONE;
                                                                };
                                                                filesaver.readyState = filesaver.WRITING;
                                                        }), fs_error);
                                                }), fs_error);
                                        };
                                        dir.getFile(name, {create: false}, abortable(function(file) {
                                                // delete file if it already exists
                                                file.remove();
                                                save();
                                        }), abortable(function(ex) {
                                                if (ex.code === ex.NOT_FOUND_ERR) {
                                                        save();
                                                } else {
                                                        fs_error();
                                                }
                                        }));
                                }), fs_error);
                        }), fs_error);
                }
                , FS_proto = FileSaver.prototype
                , saveAs = function(blob, name) {
                        return new FileSaver(blob, name);
                }
        ;
        FS_proto.abort = function() {
                var filesaver = this;
                filesaver.readyState = filesaver.DONE;
                dispatch(filesaver, "abort");
        };
        FS_proto.readyState = FS_proto.INIT = 0;
        FS_proto.WRITING = 1;
        FS_proto.DONE = 2;

        FS_proto.error =
        FS_proto.onwritestart =
        FS_proto.onprogress =
        FS_proto.onwrite =
        FS_proto.onabort =
        FS_proto.onerror =
        FS_proto.onwriteend =
                null;

        view.addEventListener("unload", process_deletion_queue, false);
        return saveAs;
}(
           typeof self !== "undefined" && self
        || typeof window !== "undefined" && window
        || this.content
));
// `self` is undefined in Firefox for Android content script context
// while `this` is nsIContentFrameMessageManager
// with an attribute `content` that corresponds to the window

if (typeof module !== "undefined") module.exports = saveAs;